Prior art German Auslegeschrift No. 1,815,214 which discloses an apparatus for the processing of molten metals by introducing evaporable additives. It includes a horizontally movable supporting structure into which is inserted a processing receptacle for the melt, the receptacle being tiltable about a horizontal axis. Thus, the receptacle can be tilted into different operational positions during the filling, processing and discharge cycles.
During filling, the receptacle, also known as a converter, is in the horizontal position, during processing the converter is swung in the upright position and during discharging it is brought into an inclined position with reference to the floor level. A significant disadvantage is that the converter pouring lip during discharging is too close to the floor level for a ladle to be placed underneath the pouring lip.
In order to remove these disadvantages, apparatuses with a tiltable frame as in U.S. Pat. No. 3,747,912 came into use, so that the converter could be tilted about an additional axis in the pouring lip region. Several other disadvantages could, however, not be removed and further ones were added. For example, the supporting structure movable on floor-mounted rails requires a large space, so that also the treatment cabin with suction pipes for the removal of metal vapors must be dimensioned correspondingly, and the rails represent a safety hazard. Still the feed position of the converter is at the same predetermined height, so that in some cases the difference in height between the discharge opening of a furnace and the filling opening of the converter must be bridged by means of a transfer ladle. The decanting and the transport of the melt causes losses in temperature and in time. Also, a back pouring of the washing iron melt into the furnace is not possible without using a transfer ladle. Further, the transport range is limited by the length of the control cables, which can be damaged due to abrasion with the floor and represent a hazard to the workers. The height of the treatment tilt axis above the floor cannot be too small due to the length of the converter and the height of the ladle. As a consequence, a worker must step up and down very frequently. Therefore, two men are required for the operation of the apparatus. A straight transport path of the converter from the filling station to the treatment cabin would often obstruct the traffic on the factory floor. A longitudinal and transverse translational transport device would, however, increase the construction costs as well as the height of the tilt axis unnecessarily. It is rather difficult and costly to exactly weigh the melt poured into this converter in which the tilting frame is supported on a pressure cell in each corner area, due to the large dead weight, the number of pressure cells and the four-point equalization.
All these disadvantages had to be accepted for a long time. In work tests, a fork lift truck modified for carrying a tiltable converter was tried out, but demonstrated no remarkable advantageous results. Although a transfer ladle between the furnace and the converter could be saved upon, two fork lift trucks equipped with converters were needed in order to carry out the necessary numbers of magnesium treatments and consequently the space requirements were larger, partly due to the frontal cantilevel mounting of the load. Due to the operation of the truck, the number of operators could not be reduced. Maneuvering and positioning of the truck exactly below and above the furnace and the ladles, respectively, was time-consuming and demanded a skilled truck operator. A weight tolerance of 3% was achieved, but only under test conditions, e.g., with clean sliding and running surfaces which are difficult to maintain under the rough foundry works conditions. Also, here it was difficult for the filling opening of the converter to follow the pouring lip of the tilting furnace because the maximum lateral adjustable working distance due to the danger of tipping over and other constructive details, could not be too large. For the same reasons, pouring of the melt back into the furnace was connected with security hazards.